Loop fastener machine control apparatus



Aug. 2, 1960 n. s. KINGsLEY LOOP FASTENER MACHINE CONTROL APPARATUS QuiNQ ATTO XN, SN` Q0, l

Filed Sept. 26, 1957 Aug. 2, 1960 D. G. KlNGsLEY LOOAD FASTENER MACHINECONTROL APPARATUS 5 Sheets-Sheet 2 Filed Sept. 26, 1957 INVENTOR. QavcKzlnsley BY xo N lill

5 Sheets-Sheet 3 D. G. KINGSLEY Aug. 2, 1960 Loop FASTENER MACHINECONTROL APPARATUS Filed sept. 26, 1957 W\\\\\\\\\\ Q L Y v m e .m 1

Aug. 2, 1960 D. G. KINGsLEY LOOP PASTENER MACHINE CONTROL APPARATUS 5Sheets-Sheet 4 Filed Sept. 26, 1957 INVENTOZR. avic Kin s e BY y 7m@ cATTO :T 15. T 114-. /wz n WL /fz u] Aug. 2, 1960 D. G. KxNGsLEY2,947,329

LOOP FASTENER MACHINE CONTROL. APPARATUS Filed sept. 26, 1957 5sheets-sheet 5 @if T1-:1.11. 1a.

INVENTOR.

,D 'd .Kzl sie BYavL g y a'@ Patented Aug. 2 1960 LOOP FASTENER MCECNTRL APPARATUS David G. Kingsley, Mountain Lakes, NJ., assigner toStapling Machines Co., Rockaway, NJ., a corporation of Delaware FiledSept, 26, 1957, Ser. No. 686,487

5 Claims. (Cl. 14093) This invention relates to apparatus forcontrolling the lengths of the loop fasteners produced on wirebound boxparts in a loop fastener machine, for example loop fastener machine ofthe general type disclosed in U.S. Patent No. 1,933,031 issued October31, 1933 and No. 2,228,304 issued January 14, 1941.

Such loop fastener machines are intended for use in combination Withbox-part stapling machines of the general type disclosed in U.S. PatentNo. 2,304,510 issued December 8, 1942. In the stapling machines, thewooden elements of the box-for example, cleats and face material-areassembled and binding wires are secured thereto by staples drivenastride the binding wires through the face material and into the cleats.The box parts (or complete box blanks) issue from the stapling machinein a continuous succession joined together by the binding wires, withsufcient space between adjacent box parts to pnovide the necessarylengths of wire for forming the loop fasteners at either end of each boxpart. This continuous succession of box parts is fed into the loopfastener machine where the binding wires are severed in the intervalbetween adjacent box parts, the resulting cut wire ends are bent to formdownwardly projecting prongs, the binding wires are then bent around inthe plane of the box parts to form loops therein and to place the prongsover the edges of the box parts, and the prongs are then driven throughthe face material and clinched against the under surface thereof tosecure the loop,VV

fasteners.

In certain types of wirebound containers, the closed loop fastenersoverlie the faces of the containers some distance from the corners. Toachieve this condition, it is necessary that the loop fasteners on oneof the adjoining box parts be shorter than the mating fasteners on theother box part. For example, it may be desired that the loop fastenerson the top and bottom of the box be longer than the mating fasteners onthe sides of the box so that the closed loop fasteners will overlie thesides of the box.

In making containers of this type heretofore, it has been necessary toset up the loop fastener machine to make loops of the proper length forone of the two types of box parts needed for a complete box and to runenough of such box parts for an entire lot without resetting themachine. For example, the machine is rst set up to run tops and bottomsand enough tops and bottoms are run to make a complete shipment; thenthe box fastener machine is reset to run sides. This necessitates theprovision of considerable storage space for storing the completed boxparts of one type until the other type of box parts can be run tocomplete the shipment.

lt is among the objects of the present invention to provide apparatusfor controlling a wirebound loop fastener machine whereby the machinecan be adapted to form loop fasteners of different lengths in successivecycles, so that equal numbers of two different types of box parts can berun concurrently on a single loop fastener machine without manualresetting of the machine. Another object is the provision of such anapparatus which is relatively simple and inexpensive in construction andwhich is adapted to be installed readily on existing loop fastenermachines, without substantial reconstruc-v tion thereof. A furtherobject is that of providing such an apparatus which is reliable inoperation and which is capable of accurate control of the length of theloop fasteners. Other objects will be apparent hereinafter.

In the drawings: Y

Figure 1 is a fragmentary top plan view of a loop` fastener machineincorporating control apparatus enrbodying features yof the presentinvention.

Figure 2 is a fragmentary vertical-longitudinal sectional view of themachine taken generally along the line 2-2 of Figure 1. g

Figure 3 is a fragmentary top elevational view of the portion of themechanism shown in Figure 2.

Figures 4 `and 5 are transverse sectional `views taken respectivelyalong the lines 4-4 and 5-5 of Figure 2.

Figure 6 is a fragmentary vertical-longitudinal sectional view of themachine taken generally along the line 6-6 of Figure 1.

Figure 7 is atransverse sectional View taken along the line 7--7 ofFigure 6.

Figure 8 is a fragmentary top elevational View of the portion of themechanism shown in Figure 6.

Figure 9 is a fragmentary vertical-longitudinal sectional view takengenerally along the lines 9-9 of Figure 1, and forming an eifectivecontinuation of the view of Figure 6.

Figure 10 is a fragmentary top elevational View of the portion of themechanism shown in Figure 9.

Figures 11 and 12 are fragmentary vertical-transverse sectional views ofthe machine taken respectively along the lines Ill- 11 and 12-12 ofFigure l.

Figures 13 and 14 are schematic diagrams of two alternative electricalcircuits for control apparatus within the scope of this invention.

In Figure 1, a continuous succession of box parts B joined together bybinding wires W is seen moving into the loop fastener machine. The boxparts B are supported in the machine on a table generally designated T,and are conveyed through the machine by means of conveyor belts C whichfrictionally engage the lateral edges of the box parts. When the boxparts reach the position shown in Figure l, at which the binding wires Win the interval between adjacent box parts are in proper position to beoperated upon by the wire cutting and forming elements of the machine,the conveyor belts C are momentarily stopped and the table T is loweredto present the binding wires to the wire cutting yand forming elements,which are actuated to sever the binding wires, form the pnongs, bend theloops and drive and clinch the prongs. Upon completion of thisoperation, the table T is again raised and the movement of the conveyorbelt C is resumed to deliver the completed box parts out of the machine.

As will readily be understood, the position in which the work is stoppeddetermines the lengths of the loop fasteners which are formed on theends of the binding wires projecting from the adjacent box parts withinthe machine. For example, if the work is stopped at a point beyond thatat which the binding wires in the interval between the adjacent boxparts are exactly centered relative to the wire cutting and formingelements, the loop fasteners on the leading box part will be longer thanthose on the trailing box part. Conversely, if the work is stopped shortof the point at which the binding wires are centered relative to thewire cutting and forming e1e` ments, the loop fasteners on the leadingbox partwill be shorter than those on the trailing box part. In generalterms, the presentv invention provides means for stopping the work indifferent positions on alternate cycles of the machine so that themachine will produce, in alternation, box parts having at each end loopsof shorter and longer lengths. Y j Y Figures 2, 3, 4 and 5 show themounting of the switch which conditions the control apparatus foroperation. This switch, whichV is referred tohereinafter as the yreadyswitch, is identified by the reference numeral 20. It is mounted on aplate 22 which is supported for longitudinal sliding movement on one ofthe Vstock support bars 24 which are adjustably secured at either end bymeans of bolts 26 and nuts 28 on the two dual-channel members 30 whichform the principal transverse framing members of the table T (Figure 1).The plate 22 is slidably supported at one face of the bar 24 by means ofbolts 32 and nuts 34 (Figure 5). Mounted on the bolts 32 within theelongated opening 24a (Figure 2) in the work support bar 24, are bushingsleeves 34a (Figure 5) which are interposed between the nuts 34 and theface of the plate 22 to prevent tightening of the nuts against the worksupport bar 24 and thereby insure that the switch plate 22 may slidefreely along the bar 24. Y

' For the purpose of adjusting the position of the switch plate 22relative to the work support bar 24, there is attached to and extendinglongitudinally from the rear end of the switch plate 22, an elongatedrod 38 the outer end of which is bent to form a handle 38a which is inconvenient position to be grasped from the output end of the machine.VThe switch plate 22 is locked in the adjusted position by means of aclamp 40 (Figures 2 and 4) which is Vsupported on a'stud 42 threadedinto the work support bar 24, the outer face of the clamp 40 beingengaged by a nut 44 threaded on the stud 42 for the purpose of applyinggripping pressure to the rod 38 between the clamp V40 and work supportbar 24.

The switch 20 is actuated by means of a lever 46 which is pivotallymounted on a bolt 4S projecting from the outer face of the switch plate22. The lever 46 is urged in a clockwise direction, as viewed in Figure2, by means of a coil spring 50 which is compressed between the lowerend of the lever and a tab 52a projecting upwardly from a bracket 52secured to the outer face of switch plate 22 by screws 54. The clockwisemovement of lever 46 under the influence of spring Sil is limited byengagement of the lower end of lever 46 with a stop screw 56 adjustablythreaded through a tab 52h projecting upwardly from the bracket 52. Y Y

The spring 50 thus tends to maintain the lever 46 in the positionindicated in broken lines in Figure 2 at which the upper end ofthe'lever projects into the path of the face material F of the box partsB (Figure 1), moving lintoand through the loop fastener machine in thedirection indicated by the arrow at the upper right-hand side of Figure2. In this upper position of lever 46, an adjustable switch actuatingscrew 62 threaded through a boss `64 in the lower portion of lever 46depresses the plunger 20a of ready switch `20.

However, the upper end of the lever 46 is rocked in a counterclockwisedirection to the position shown in full lines in Figure 2 and held downin such'position by engagement of the upper end of the lever with theface material F of a box part B moving into and through the loopfastener machine. In this depressed' position the screw 62 of leverV 46will release the plunger 20a of ready switch 20.

The upper end of the lever 46 is provided with a flattened portion 46awhich is parallel to the lower face of the face material F of a box partresting upon the work support bar 24 when the lever 46 is in thedepressed position in which it is shown in full lines in Figure 2. ThisHattened portion 46a is sufficiently long that the lever 46 cannot moveupwardly except in the interval between adjacent box blanks in otherwords, the length of the portion 446a is greater than thegreatest-spacing between the slots of any crate construction to behandled in the machine. Thus, the plunger 20a of ready switch 20 will bedepressed at all times during the operation of the machine except duringpassage of a space between separate box parts or box blanks.

lAs will be more fullyrdescribed hereinafter, the switch 20 is connectedto control the supply of compressed air to a pair of pneumaticcylinders, one of these cylinders being identied by the referencenumeral 66 in Figure 6. These two cylinders formparts of two identicalvstopswitch mechanisms which are mounted on the table T of the machinefor engagement with opposite ends of the leading edge of each box partor box blank moving into the machine; Since these two mechanisms areidentical, only one of them is shown and described.

For handling box parts and blanks of relatively small width, only one ofthese mechanisms need be provided. But where the box parts or box blanksare of relatively great width, greater accuracy of loop length can beachieved by using two such mechanisms,V one near either end of the boxparts or blanks.

As may be seen in Figure 6, each of the stop-switch mechanisms includesa work Vsupport bar 70 which is adapted to engage the undersurface ofthe facematerial F of the'box part B near one side thereof. The worksupport bar 70 is mounted for longitudinal movement in a pair of blocks72, one of which is shown at the right in Figure 6 and the other ofwhich is shown inV Figure 9, these two blocks being secured on thetransverse members 30 of the table T (tFigure 1). To provideforlongitudinal movement of the work support bar 70, the bar carries ateach end a set of four rollers 74, Ytwo at either side, which arerotatably mounted on bolts 76. TheA rollers 74 are received in guideslots 72a in the blocks 72, the slots 72a being of a width only slightlygreater than the diameter of the rollers '74 to confine the rollersagainst vertical movement while permitting them to roll along the slotsfor longitudinal movement of the bar 70 relative to the blocks 72.

To limit the longitudinal movement of the bar 7i), there are provided apair of stop screws 78 (Figures 6 and 9) which are adjustably threadedIthrough tabs 80 projecting laterally from the bar 70. The heads orthese screws are adapted for engagement with the inner ends of theblocks 72 and the adjacent edges of the transverse members 30. The stopscrews 78 are so adjusted that when one of them is in engagement withits respective block 72, as shown in Figure 6, the other is spaced ashort distance from its respective block 72, as shown in Figure 9, andvice versa. Thus, the work support bar 70 is permitted to movelongitudinally between two positions spaced apart a short distancedepending upon the adjustment of the stop screws 7S.

The work support bar 70 is moved to one or the other of its two extremepositions by a pneumatic cylinder 82 (Figure 6). The outer end of thecasing of this cylinder y'82 is pivotally secured by a pin `83 to albracket 84 depending from the forward end of an arm 86 which is securedto and extends forwardly from the underside of the transverse member 30at the front end of the table T. The piston rod 87 of the cylinder 82 ispivotally secured by means of a clevis 88 and pin 89 to the lower end ofan arm 90 which projects -downwardly from the work support bar 70 `andwhose upper end is rigidly secured thereto.

By means which will be described more particularly hereafter, thepneumatic cylinders 82 of the two stopswitch mechanisms are connectedfor simultaneous movement of their respective work support bars in thesame direction so that both of the work support bars are either in theforward position, at which they are shown in Figures 6 and 9, or are intheir rearward position at which the head of the rear stop screw 78(Figure 9) is against the rear block 72. Y Y t Secured at one face ofthe work support Vbarv70 is a stop switch 92 (Figures 6 and 8) theplunger 92a of which is actuated by a screw 94 adjustably threadedthrough the end of a U-shaped arm 96 which extends beneath the worksupport bar 70 'and around to its opposite side where it is attached toby means of screws 100 to a switch actuating member 98. This member 98is pivotally attached by means of a bolt 102 and bushing 103 (see Figure7) to the upper end of a link 104 whose lower end is pivotally attachedby a bolt 106 and bushing 107 (Figure 7) to the work support bar 70.Thus the switch actuating member 98 may not only pivot about the bolt102 but it may also move longitudinally by pivoting of the link 104about the bolt 106.

` The switch actuating member 98 is urged forwardly (toward the right asviewed in Figure 6) by means of a coil spring 108 which is tensionedbetween the bolt 102 and a stud 110 projecting from the face of the worksupport bar 70. Forward movement `of the member 98 under the influenceof the spring 108 is limited by a pin 112 which projects from the outerface of the member 98 yand engages the adjacent edge of the link 104. Aswill be understood, as the member 98 moves forwardly from the point atwhich the link 104 is perpendicular to the member 98, the angle betweenthem decreases to the point where the `edge of the link 104 comes intoabutment with the pin 112, thereby preventing further forward movementof the member 98. The member 98 may be moved rearwardly from thisposition, against `the resistance of the spring 108, to the point wherea vertical shoulder 98a near the rear end of member 98 comes intoabutment with a roller 114 which is rotatably supported on the face ofmember 70 by a screw 116 (Figure 8).

The member 98 is urged in a clockwise direction about its pivot bolt 102by a coil spring 118 which is tensioned between a pin 120 projectingfrom the forward (right-hand) end of the member 98 and a pin 122 securedto andprojecting forwardly from the lower end of arm 90. The clockwisemovement of the member 98 under .the inuence of the spring 118 islimited by engagement of the roller 114 with an upwardly facinghorizontal edge portion 98h of the member 98.

Near the rearward end of the switch actuating member 98, a stop block124 is secured to the upper edge of the member 98 and projects upwardlytherefrom in position, when the member 98 is in its extreme clockwiseposition, as shown in Figure 6, to engage the leading edge of the facematerial F of each box part moving into the machine. However, the stopblock 124 may be removed from the path of the face material F by rockingthe member 98 in a counterclockwise direction about its pivot bolt 102against the resistance of the spring 118. This is accomplished by thepneumatic cylinder 66 previously referred to. The casing of the cylinder66 is secured to the arm 90 which projects downwardly from the worksupport bar 70, while the piston rod 126- of the cylinder 66 has securedat its upper end a finger 128 which overlaps the outer face of themember 98 at its right-hand end and which carries a roller 138 which isadapted to engage ia generally horizontal lower edge 98C of the member98 when compressed air is supplied to the cylinder `66 to raise itspiston rod 126. Such movement of the piston rod 126 rocks the member 98in a counterclockwise direction 'against the resistance of the spring118 and removes the stop block 124 from 'the path of the face material Fof the box parts. t1/hen the supply of compressed airis removed from thecylinder 66, the spring 118 rocks the member 98 again in a clockwisedirection to the position shown in Figure 6 at which the stop block 124is in position to engage the leading Vedge of the face material F.

When the stop block 124 is thus engaged by the leading `edge of the facematerial F of a box part B moving into the machine, the "member 98 ismoved rearwardly (to the left as shown in Figure 6) to the point wherethe shoulder 98a of the member 98 engages the roller 114 on the worksupport bar 70. During this rearward movement of the member 98, thescrew `94 (Figure 8) depresses the plunger 92a of the stop switch 92,actuating the switch which, through a circuit to be describedhereinafter, stops the movement of the conveyor belts and causes thetable T and the wire cutting and forming elements of the machine to bedriventhrough a loop forming cycle.

Two additional switches which play a part in the electrical controlcircuit for the apparatus are shown in Figures 11 and 12. The switchshown in Figure 11, which is referred to hereinafter as the resetswitch, is identiiied by the reference numeral 132. It is mounted on abracket 134 secured to the forward end of one of the two side frames 136of the machine (see also Figure 1). The plunger 132er of the switch isactuated by means of a screw 138 which is adjustably threaded through anarm 140 secured to the adjacent longitudinal framing member 142 of thetable T. When table T is in its normal upper position, in which it isshown in Figure 1l, the screw 138 depresses the plunger 1325.1. When, atthe start of the loop forming cycle, the table T is lowered to presentthe box parts to the wire cutting and forming elements of the machine,the screw 138 releases the plunger 13251.

The switch shown in Figure l2, which is an indexing switch-Le., it isopened and closed on alternate actuations-is identified by the referencenumeral 144. This switch 144 is mounted on a plate 146 which is securedat the rearward end of the side frame 136 previously referred to (seealso Figure l). This switch 144 is provided with a laterally projectingpivotally mounted arm 144g which carries at its outer end a roller 14411which lies in the path of a block 148 carried at the outer end of an arm150 secured near the rearward end of the aforementioned longitudinalframing member 142 of the table T. Each time the table T descends fromits normal uppe position, in which it is shown in Figure 12, theinclined lower end 148a of the block 148 comes into engagement with theroller 1441: on the actuating arm 14451 of the switch 144, rocking thearm 144a in a counterclockwise direction, as viewed in Figure 12, andindexing the switch from one position to the next. 1

Figure 13 shows one illustrative electrical circuit for the controlapparatus. In Figure 13 this electrical circuit is shown in thecondition which obtains in the interval between loop forming cycles,prior to the arrival into the machine of the interval between the next.pair of box parts to be operated upon. As may be seen, the ready switch20, which is a normally open single-pole singlethrow switch, is closedby Virtue of the fact that the lever 46 (Figure 2) is held in the lowerposition in which it is shown in full lines in Figure 2 by engagementwith the undersurface or' the face material F of a box part movingthrough the machine, causing the screw 62 to depress the plunger 20a ofthe switch. The closure of this switch 20 maintains the supply ofcurrent from the power lines 152 and 154 (Figure 13) through the winding156:1 of a relay 156, the normally open holding contacts 15@ of therelay being held closed by the energization of the winding 15661. Therelay 156 is also provided with another pair of normally open contacts156C which are closed by the energization of the winding 156g and theseclosed contacts 156C supply current from the power lines 152 and 154 tothe winding 158 of the solenoid valve which controls the supply ofcompressed air to the cylinder 66 (Figure 6). When this winding 158 isthus energized, compressed air is supplied to the cylinder 66 tomaintain its piston rod 126 in an upper position and hold the switchactuating member 98 rocked in a counterclockwise direction against theresistance of the spring 118, thereby holding the stop block 124 out ofthe path of the face material F of the box parts moving through themachine.

When the interval between the next pair of box parts to be operated uponin the machine comes opposite the lever `46` (Figure 2) the lever 46 isallowed to be moved in a clockwise direction by the spring 50 to theposition shown in broken lines in Figure 2, releasing the plunger a ofthe ready switch 20 and opening the switch. As may be seen in Figure 13,the opening of the ready switch 20 breaks the circuit to the winding156a of the relay 156 and opens its contacts 156b and 156er. The openingof the holding 'contacts 156b prevents reenergization of the relaywinding'156a until the next Vtime the reset switch 132 is closed, eventhough the switch 20 will have been reclosed in the meantime. Theopening ofthe relay `contacts 156C breaks the circuit to the Winding 158of the solenoid valve and removes the ysupply of cornpressed air fromthe cylinder 66 (Figure 6). This permits the spring 118 to rock theswitch actuating member 98 in a clockwise direction to the positionshown in Figure 6 at which the stop block 124 is in the path of the facematerial F of the oncoming box part.

When the leading edge of the face material F of the oncoming box partengages the stop block 124, the switchactuating member v98 is movedrearwardly (to the left as viewed in Figure 6) against the resistance ofthe spring 108 to the point where 4the shoulder 98a comes into abutmentwith the roller 114. During this movement of the member 9S, the stopswitch 92 is closed Referring again to Figure 13, the closure of thestop switch 92, which is a normally open single-pole single-throwswitch, supplies current from Vthe power lines 152 and 154 to theWinding 160a of a relay 160. This closes the normally open contacts 160band 160C of the relay 160 and supplies current from the power lines 152and 154 to a pair of solenoids 162 and 164 which control the clutcheswhich drive the conveyor belts C (Figure 1), the table T and the Wirecutting and forming elements of the machine. Energization of thesolenoid 162 disengages the clutch which drives the conveyor belts C andapplies the brakes to stop the conveyor belts and thereby stop themovement of the box parts B. Energization of the solenoid 164 engagesthe clutch which drives the table T and the Wire cutting and formingelements of the machine. This clutch is of the type which, once engaged,remains engaged for one complete revolution and is then automaticallydisengaged. When this clutch is engaged, it causes the table T to belowered to present the binding wires to the Wire cutting and formingelements and causes the latter elements to be driven through a loopforming cycle to sever the wire, bend the resulting cut wire ends toform prongs, bend the wires again to form loops therein and to place theprongs vover the edges of the face material of the box parts to drivethe prongs through the face material and clinch them over against theundersurface thereof. The construction and `operation of these clutchesis ydescribed in greater detail inthe aforementioned Patent No.1,933,031.

As the table T is Vlowered at the commencement of the loop formingcycle, the plunger 132z (Figure 11) of the reset switch 132 is released,allowing this switch 132, which is a normally closed single-polesingle-throw switch, to close. As many be seen in Figure 13, the closureof this reset switch 132 supplies current to the winding 15651 of therelay 156 energizing the relay and closing its normally open contacts156b and 156e.

r[The closure of the holding contacts 15611 maintains the energizationof the winding 15601 of the relay 156 through the ready Yswitch 20,which by now will have been reclosed by depression of the lever 46(Figure 2) by engagement with the undersurface of the face material F.Thus, even after the switch 132 is reopened by return of the table T toits normal upper position at the conclusion of the loop forming cycle,the relay 156 will remain energized preparatory for the next cycle.

The closure of contacts 156C of relay 156 again energizes therwinding158 of the solenoid valve which controls the supply of compressed air tothecylinder 66 (Figure 6). `This causes compressed air to be supplied tocylinder 66, raising its-piston rod 126 and rocking Athe member 98 in acounter-clocklwse direction about its pivot bolt 102. against theresistance of spring 118 to the point where stop block 124 is removedfrom-the path of the face material F. This readies the machine forresumption of the feeding of box parts B-uponcompletion of the loopforming cycle.

As the stop block 124 moves out of engagement-with the leading edge ofthe face material F, the spr-ing 108 again moves the switch actuatingmember 98 forwardly, causing the screw 94 (Figure 8) to release theplunger 92a of the stop switch 92 and open the switch. Asmay be seen inFigure 13, the opening of stop switch 92 deenergizes the relay 160,opening its contacts `b and 169C. solenoid 162 of the clutchwhich-drives the conveyor belts C (Figure 1). However, this clutch isheldout of engagement during the entire time the table T is lowered by amechanical interlock more fully disclosed in the aforementioned PatentNo. 1,933,031. Although the opening of the contacts 160e deenergizes thesolenoid 164 of the clutch which drives the table and the wire cuttingand forming elements of the machine, as mentioned hereinabove thisclutch will remain engaged for one full revolution of the drive shaft,and these elements will be driven through a complete loop forming cyclebefore stopping. Y

The lowering of the table T at the commencement of each loop formingcycle actuates the indexing switch 144 (-see also Figure l2) from oneposition to the next. This switch 144 is thus open during one loopforming cycle and closed during the next.

As may be seen in Figure 13, the s'witch 144 is connected in series,`across the power Ylines 152 `and-154, with the winding 166 of thesolenoid valve which controls the supply of compressed air to thepneumatic cylinder 82 (Figure 6). 'Thus this solenoid valveis openduring one loop forming cycle and closed during the next, to cause thecylinders 82 to shift the two Work support bars`7 0 in unison to theirextreme forward position as shown in Figure 6 on one loop forming cycleand to their extreme rear position on the next. This changes thepositions of the stop block 124 and causes the work to be stopped indifferent positions on alternate cycles. Thus the machine will produce,in alternation, box parts having short loops at each end and box partshaving long loops at each end.

As the loop forming cycle is completed, the table T is again raised andthe mechanical interlock of the clutch which controls the drive to theconveyor belts C is released, allowing the movement of the conveyorbelts to be resumed to :feed the completed box parts out of the machine.The electrical circuit is then in the condition in which it is shown inFigure 13, and is ready for the next cycle.

Figure 14 illustrates an alternative electrical circuit which is.employed in a modified embodiment of the present invention. In thisembodiment, the two stopswitch mechanisms, rather than being shiftedsimultaneously to their forward and rearward positions, are fixed inposition, one in its extreme forward position and one in its extremerearward position. As will be understood, in this embodiment the worksupport bars 70 (Figures 6 and 9) need not be moved between successivecycles of the machine, and may be fixed in position. lThis eliminatesthe .need for the pneumatic cylinders 82 (Figure 6) which shift thesestopswitch assemblies between their respective positions, and for therollers 74 which facilitate such movement. Instead a simple clampingarrangement such as is provided for the ready switch mechanism (Figure2) may beprovided to permit adjustment of the positions of the stopswitch :assemblies for variation of the loop lengths. Sincethe twostop-switch mechanisms-are ini diier-` The opening of contacts 160bdeenergizcs the ent positions, their respective stop blocks (Figure 6)are displaced relative to each other longitudinally of the machine. Bymeans of the circuit shown in Figure 14, rst one and then the other ofthe two stop blocks is moved into position to engage the face matenial Fof the box parts B.

In Figure 14 the circuit is shown in the condition which obtains priorto arrival in the machine of an interval between adjacent box parts tobe operated upon. The ready switch 20 is closed to energize the relay156 through its closed holding contacts 156b, The energization of therelay 156 also maintains its contacts 156e closed to supply currentthrough the contacts 170e of a double-pole double-throw indexing switch170 to the winding 172 of the solenoid valve which controls the supplyof compressed air to the cylinder 66 (Figure 6) of one of the twostop-switch mechanisms. The winding 174 of the solenoid Valve whichcontrols the supply of lair to the cylinder 66 of the other stop switchmechanism is also energized through the other contacts 170b of theindexing switch `170. Thus, compressed air is supplied to the cylinders66 of both of the two stopswitch mechanisms to maintain their stopblocks 124 out of the path of the oncoming box parts.

When the box parts have advanced to the point where the space betweenadjacent box parts or box blanks is opposite the lever 46 (Figure 2) ofthe ready switch 20, the lever will move upwardly into this space,depressing the plunger 20a of the ready switch 20 and opening theswitch. As may be seen in Figure 14, the opening of ready switch 20 willdeenergize relay 156, opening its contacts 15611 and 156e. The openingof contacts 156C will deenergize winding 172 and allow the stop block124 (Figure 6) of one of the two stop-switch mechanisms to be movedupwardly by spring 118 into the path of the leading edge of the facematerial F of the oncoming box part. When this stop block 124 is thusengaged and moved rearwardly, against the resistance of the spring 108,the stop switch 92 (Figure 14) will be closed, energizing relay 160 andclosing its contacts 160b and 160C to actuate the solenoids 162 and 164which control the clutches which drive the conveyor belts C (Figure l),the table T and the wire cutting and forming elements of the machine.Thus, as previously described, the conveyor belts will be stopped, thetable lowered and the machine will be driven through a loop formingcycle.

As the table T is lowered, a reset switch 132 will be closed, againenergizing relay 156, closing its contacts 156e and energizing thewinding 172 of the solenoid valve which controls the supply ofcompressed air to cylinder 66 (Figure 6). This will cause compressed airto be supplied to cylinder 66, again moving the active stop block -124from the path of the box parts so that the box parts may be deliveredout of the machine when the movement of the conveyor belts C is resumed.

The lowering of table T will also actuate the indexing switch 170, inthe manner previously described in connection with switch 144 (fFigure12), to throw it from the position show-n in :Figure 14 to its`alternate position, transposing the connections of the windings 172 and174 of the solenoid valves of the two stop switch mechanisms. Thus, onthe next cycle of the machine the opening of the ready switch 20 willdeenergize the winding 174 of the solenoid valve of the other stopswitch mechanism to remove the supply of compressed air from itscylinder 66 (Figure 6) and allow its stop block 124 to be moved intooperative position.

It will thus be seen that on one cycle of the machine one of the twostop blocks is in operative position to engage and stop the box parts,while on the next cycle the stop block 124 of the other stop switchassembly is in operative position. Thus, on one cycle the box parts arestopped in one position and on the next cycle they are stopped in theother position, so that box parts having 10 long loops and box partshaving short'loops are produced on alternate cycles of the machine.

From the foregoing description, it will be appreciated that the presentinvention provides apparatus for automatically controlling the length ofthe loops being produced in the loop fastener machine to accomplish theaforementioned and other desirable objectives. However, it should beemphasized that the particular embodiments of the invention which areshown and described herein are intended as merely illustrative of theprinciples of the invention rather than as restrictive of the scopethereof or of the coverage of this patent, which is limited only by theappended claims.

ln some of the claims, the cylinder 66 (lFigure 6) is referred to `asthe first power means and the cylinder 82 (Figure 6) is referred to asthe second power means. The switch Ztl (Figures 2 and 3) is referred toas the first control means and as the ready switc switch 132 (Figures 1and 1l) is referred to as the second control means and as the resetswitch; and switch 144 (Figures 1 and `12) is referred to as the thirdcontrol means and as the selector switc I claim:

l. AIn a machine for forming loop fasteners from binding wiresinterconnecting a spaced series of wirebound box parts, apparatus foradapting said machine to form loop fasteners of different lengths insuccessive cycles comprising, a stop assembly -mounted in said machinefor longitudinal movement, said stop assembly including a movable stopelement positioned for engagement with a predetermined portion of eachbox part moving into said machine, a stop switch actuated by said stopele-V ment, said stop switch being connected to control the work feedingand loop forming mechanisms of said machine, whereby actuation of saidstop switch by said box parts renders said feeding mechanism ineffectiveto feed the box parts and causes said loop forming mechanism to bedriven through a loop forming cycle, power means for moving said stopassembly longitudinally between two positions, at which said stopelement will respectively actuate said stop switch to stop saidwirebound box blanks with the toop forming mechanism at opposite sidesof the center of a space between adjacent box parts, and control meansfor controlling said power means, said control means being mounted onsaid machine in such position as to be engaged and actuated by arelatively movable part therein during each loop forming cycle of saidmachine to cause said power means to shift said stop assembly toalternate ones of said two positions on successive cycles.

2. ln a Lmachine for forming loop fasteners from binding wiresinterconnecting a spaced series of wirebound box parts, apparatus foradapting said machin-e to form loop fasteners of different lengths insuccessive cycles comprising, a stop assembly mounted in said machinefor longitudinal movement, said stop assembly including a stop elementwhich is vertically movable between an extended position at which itprojects into the path of a leading `edge of said box parts and aretracted position clear of said path and which is also longitudinallymovable by engagement with the moving box parts, a stop switch actuatedby the longitudinal movement of said stop element, said stop switchbeing connected to control the work feeding and loop forming mechanismsof said machine, whereby actuation of said stop switch by said box partsrenders said feeding mechanism ineffective to feed the box parts andcauses said loop forming mechanism to be driven through a loop formingcycle, first power means for vertical movement of said stop element,iirst and second control means for controlling said rstl power means,said first control means being arranged to be actuated by the approachof a box part into said machine and to cause movement of said stopelement to said extended position, said second control means l'1'1 beingarranged to be actuated during an earlier part of each loop formingcycle of said machine and to cause movement of said stop element to saidretracted position, second power means for longitudinal movement of saidstop assembly between two positions at which said stop element willrespectively actuate said stop switch to stop said wirebound box blankswith the loop forming mechanism at opposite sides of the center of aspace between adjacent box parts, 'and third control means forcontrolling said second power means, said third control means beingmounted on said machine in such position as to be engaged and actuatedby a relatively movable part therein during a later part of each loopforming cycle of said machine to cause said third power means to movesaid stop assembly longitudinally to alternate ones of said` twopositions on successive cycles,

3. 'In a machine for forming loop fasteners from binding wiresinterconnecting -a spaced series of wirebound box parts, apparatus foradapting said machine to form loop fasteners of different lengths insuccessive cycles comprising, a stop assembly mounted in said machinefor longitudinal movement, said stoprassembly including a stop elementwhich is transversely Vmovable between an extended position at which itprojects into the path of a leading'edge of said boxpparts and aretracted position clear of said path and which is also longitudinallymovable by engagement with the moving box parts, a stop switch actuatedYby the longitudinal movement of said stop element, said stop switchbeing connected to control the work feeding and loop forming mechanismsof said machine, whereby 4actuation of said stop switch by said boxparts renders said feeding mechanism ineffective to feed the box partsand causes said loop forming mechanism to be driven through a loopforming cycle, rst electrically controlled power means coupled to saidstop element for transverse movement thereof, -a ready switch and areset switch connected to control said rst power means, 'said readyswitch being arranged to be actuated by the approach of a box part intosaid machine to cause transverse movement of said stop element to saidextended position, and said reset switch being arranged to be actuatedby a relatively moving part of said machine during each loop formingcycle to cause transverse movement of said stop element to saidretracted position, secondelectrically controlled power means forlongitudinal movement of said stop assembly between two positions atwhich said stop element will respectively actuate said stop switch tostop said wirebound box blanks with the loop forming mechanism atopposite sides of the center of a space between adjacent box parts, anda selector switch connected to control said second power means, saidselector switch being arranged to be actuated by a relatively movingpart of said machine during a later part of each loop forming cycle to-actuate said second powerrneans for longitudinal movement of said stopassembly to alternate positions on successive cycles.

4. In -a machine for forming loop fasteners from binding wiresinterconnecting a spaced series of wirebound box parts, apparatus foradapting said machine to form loop fasteners of different lengths insuccessive cycles comprising, Ia pair of stop assemblies mounted in saidmachine, each of said stop assemblies including a stop element which islongitudinally movable and is also transversely movable between anextended position at which it pro- 55 jects into the path of a leadingedge of said box parts and a retracted position clear of said path and astop switch actuated by the longitudinal movement of said stop elementwhen said stop element is engaged by said leading edge, said stopassemblies being mounted with their respective stop elements positionedto be engaged by said leading edge an actuate said stop switch with theloop forming mechanism at opposite sides of the center of a spacebetween adjacent box parts, said stopy switch being connected to controlthe work feeding and loop forming mechanisms of said machine, wherebyactuation of said stop switch by said box parts renders said feedingmechanism ineffective to feed the box parts and causes said loop formingmechanism to be driven through a loop forming cycle, power means coupledto each of said stop elements for selective movement thereof betweensaid retracted and extended positions, control means connected tocontrol said power means, said control means being arranged foractuation by a moving part of said machine once each cycle of saidmachine whereby said control means is indexed to cause said power meansto move said stop elements alternately into said projected position onsuccessive cycles of said machine.

5. In a machine for forming loop fasteners from binding wiresinterconnecting a spaced series of wirebound box parts, apparatus foradapting said machine to form loop fasteners of different lengths insuccessive cycles comprising, a pair of stop assemblies mounted in saidmachine, each of said stop assemblies including a stop element which islongitudinally movable and is also transversely movable between anextended position at which it projects into the path of a leading edgeof said box parts and a retracted position clear of said path and a stopswitch actuated by the longitudinal movement of said stop element whensaid stop element is engaged by said leading edge, said stop assembliesbeing mounted with their respective stop elements positioned to beengaged by said leading edge and actuate said stop'switch with the loopforming mechanism at opposite sides of the center of a space betweenadjacent box parts, said stop switch being connected to control thework-feeding and loop forming mechanisms of said machine, wherebyactuation of said stop switch by said box parts renders said feedingmechanism ineffective to feed the box parts and causes said loop formingmechanism to be driven through a loop forming cycle, a pair ofelectrically controlled power means, one coupled to each of said stopelements for movement thereof between said retracted and extendedpositions, a control circuit for controlling said power means, saidcircuit including a selector switch arranged to be actuated by arelatively moving part in said machine once during each machine cycleand adapted to connect alternate ones of said power means into saidcontrol circuit on successive cycles, a ready switch arranged to beactuated by the approach of a box part into said machine and connectedto actuate the power means then in said circuit to move the stop elementassociated therewith to said extended position, and a reset switcharranged to be actuated by a relatively moving part of said machineduring each cycle and connected to actuate the power means then in saidcircuit to move its stop element to said retracted position.

References Cited in the le of this patent UNITED STATES PATENTS UNTTTDSTATES PATENT QFTTCS CE1 'HHCATE F CORRECTION Patent N0 a 2g947329August 2, 1960 David G'e Kingsley It is herebjr certified that errorappears n the-printed specification of' the above numbered patentrequiring correction and that the said Letters Patenl'J should read ascorrected below.

Signed and sealed this 31st day of January 1961a (SEAL) Attest:

1 ARL HT7 AXLINE ROBERT C. WATSON Attesting Ofcer Commissioner ofPatents

